//Accepted
#include <vector>
#include <set>
#include <algorithm>
#include <string>
#include <cmath>
#include <queue>
#include <map>
#include <iostream>
#include <list>
#include <deque>
#include <cstdio>
#include <cstdlib>
using namespace std;

int main (){
	//freopen("in.txt", "r", stdin);//freopen("out.txt", "w", stdout);
	int n, i=1, f=1;
	scanf("%d",&n);
	for(; i<=n;++i)f*=i;
	printf("%d",f);
	return 0;
}
